1. Field of the Invention
The present invention relates to an image reader in which read-scan of original images is performed by the use of a line sensor and to an image reproducing system having a read scanning section of the similar structure to that of the above image reader.
2. Related Art
Through the recent development of image recording technology, recording speed has been remarkably increased. In contrast with the improvement of recording speed, there is a practical limit to the increase of image reading speed because images are read by a scanner driven in a reciprocating manner so that image reading speed not only device a speed at which images are actually read, but is associated with the speed of the scanner as it accelerates/decelerates and as it returns to the initial position.
It is therefore difficult to increase the speed of continuous recording operation when multiple coping of one original document or multiple copying of multiple original documents is performed.
One known method for overcoming the foregoing problem is such that when multiple copying of one original document is carried out, images read by a scanner are once stored in a page memory and then the stored images are repeatedly read out and recorded. This technique is disclosed in Japanese Patent Publication No. 28867/1990.
The page memory taught by the above prior art is effective when continuous recording of one original document is carried out at high speed. However, when multiple copying of multiple original documents is carried out, high-speed copying cannot be always achieved by simply employing a large-capacity memory such as the page memory because the time required for the replacement of original documents is also a key to be considered for saving time. It is true in view of the above point that the prior art does not effectively utilize the large-capacity memory, i.e., the page memory.